Reversible self-propelled plate compactor

ABSTRACT

A reversible self-propelled plate compactor which includes at least one motor driven vibrator assembly, a housing for each vibrator assembly is mounted to one end of an arm, an opposite end of the arm is attached to a tamper plate by a flex mounting members, the forces generated by the vibrator assembly are directed to the tamper plate only by way of its associated arm and the flex mounting members, the direction of the self-propelled travel being irrespective of the direction of rotation of the shaft of the vibrator assembly.

BACKGROUND OF THE INVENTION

1. Field of the Invention

With regard to the classification of the art, this invention is believedto be found in the general class entitled: "Road Structure, Process andApparatus", and more particularly to the subclasses pertaining to"Tamper Apparatus".

2. Description of the Prior Art

Plate compactors or Tampers are known in the art. Reversible platecompactors are the subject of several known U.S. patents. These knownpatents are U.S. Pat. Nos. 3,001,458 issued to Croucher on Sep. 26,1961; 3,603,224 issued to Dresher on Sep. 7, 1971; 3,832,080 issued toStoecker on Aug. 27, 1974; 3,972,637 issued to Sutherland on Aug. 3,1976; and 5,149,225 issued to Artzberger on Sep. 22, 1992.

U.S. Pat. Nos. 3,001,458 and 3,832,080 employ the principles ofadjusting the phase angle relationship of a pair of counter-rotatingeccentrics. This type of apparatus employs complex adjusting means whichhas a relatively short service life as a result of the stress and theenvironment in which operates.

U.S. Pat. No. 3,972,637 mounts the tamper plate on a vertical axis. Thismounting allows the eccentric drive to be rotated about a vertical axiswith respect to the compactor plate. Space considerations at the worksite have made this reversing feature unusable. In many cases, thecompactor must be reversed while the operator is close to a corner.

U.S. Pat. No. 3,603,224 discloses a plate compactor having a pair ofeccentrics. The direction of movement is determined by the direction ofrotation of the eccentrics. This arrangement requires a reversibletransmission which has been found to be very expensive while loweringthe service life of the compactor.

U.S. Pat. No. 5,149,225 discloses a pair of eccentrically weightedshafts fixed to a compactor plate. Each of the eccentrically weightedshafts is independently rotated by a transmission mechanism. Thisarrangement requires that the eccentrically weighted shafts be rotatedin opposite directions for providing the desired directional movement.

All of the known reversible plate compactors include somewhatsophisticated drives. These drives add complexity to the apparatus aswell as cost. The complexity of some of the arrangements require that insome cases elaborate repair parts be maintained at the work site. It hasbeen found that an apparatus which provides reversing capability at areasonable cost is needed. This desired plate compactor should include asimplicity of construction, operation, and maintenance.

The present invention solves the indentified limitations of the priorart. The present invention also includes a plate compactor whosereversing capabilities are irrespective of drive rotation.

SUMMARY OF THE INVENTION

The present invention may be summarized with respect to its objects. Itis an object of this invention to provide and it does provide areversible plate compactor which is simple in construction; easy tomaintain and inexpensive to repair.

It is another object of this invention to provide and it does provide aplate compactor whose reversing capabilities are irrespective of thedirection of rotation of the eccentric shafts. This allows the use ofcommercial drive without using a change of direction transmission.

All aspects of the present invention disclose a self-propelled platecompactor comprising: a tamper plate having a tamper side for contactingmaterial to be compacted; an engine carried on a mounting plate, themounting plate being selectively shaded; the mounting plate beingresiliently attached to the tamper plate for isolating the mountingplate and the engine from the tamper plate vibrations, the engine havinga drive means attached to an output shaft; a weight being eccentricallycarried on a vibrator shaft for imparting vibratory motion when rotatingby way of a driven means selectively driven by said drive means, theshaft having selected portions being journalled in at least onevibratory housing, this vibratory housing being attached only to one endof an arm, the opposite end of the arm having a flex mounting means forattaching to an interior side of the tamper plate, the interior sidebeing opposite to the tamper side, an axis of the flex mounting meansbeing transverse to a direction of self-propelled travel; and whereinthe vibrator housing and said arm are selectively tilted about the axisat a predetermined angular position with respect to a plane which isparallel to the tamper side, for directing substantially all of theforces necessary for self-propelled travel into said tamper plate onlyby way of said flex mounting means irrespective of the direction ofrotation of said vibratory shaft.

In one embodiment the flex mounting means includes a pivoting meanswhich allows a single vibratory housing to be selectively swung from oneend of the tamper plate to the other for providing reversibleself-propelled travel. Isolation pads absorb tangential forces beforereaching the end of the tamper plate. This first embodiment employs aintermediate transfer shaft whose axis is coincident with the pivotingaxis to provide a continuity of drive from the drive means to the drivenmeans.

Another embodiment discloses two vibratory housings which areindependently driven. This second embodiment includes a common pivotalmounting for the vibratory housings as well as an intermediate transferdrive means, and a V-belt tensioning means in the form of a pair ofwheels mounted on a rocker-type lever.

Still another embodiment discloses a first alternate for a flex mountingmeans.

Yet another embodiment of the plate compactor further includes a secondvibratory housing which is rigidly mounted on the one end of the tamperplate in addition to the flex mounting of its first vibratory housing.

In the context of this invention a flex mounting means is one whichallows small predetermined amounts of oscillating movement of avibratory housing in a direction at right angles to the plane of an armattached to the vibrator housing. This flex mounting positions thevibratory housing in spaced relationship to the tamper plate. Thisspaced relationship allows substantially all of the self-propellingforces to be directed to the tamper plate only through the flex mountingmeans.

In addition to the above summary, the following disclosure is detailedto insure adequacy and aid in the understanding of this invention. Thisdisclosure, however, is not intended to cover each new inventive conceptno matter how it may be disguised either by variations in form oradditions by further improvements. For this reason, there has beenchosen specific embodiments of a reversible plate compactor apparatus.The specific embodiments have been chosen for the purpose ofillustration and description as shown in the accompanying drawingswherein:

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 represents a side elevational view of an apparatus of the presentinvention, This view being partly diagrammatic for ease of illustration.

FIG. 2 represents an elevational view of one end of the apparatus, thisview being partly in section to show a pivoting means arrangement.

FIG. 3 represents a fragmentary side elevational view of a vibratorhousing and its pivotal mounting, this view being partly schematic forease of illustration.

FIG. 4 represents an alternate arrangement for the pivot connection ofthe vibrator to a compactor plate.

FIG. 5 represents a side elevational view, partly schematic, of a secondembodiment of the present invention, this second embodiment utilizes apair of vibrator housings pivotally mounted to the compactor plate.

FIG. 6 represents a plan view, partly schematic, of the secondembodiment of the present invention, this view being taken along line6--6 of FIG. 5.

FIG. 7 represents a side elevational view of a third embodiment of thepresent invention, this view being shown partly diagrammatically forease of illustration.

In the following description and in the claims, various details areidentified by specific names for convenience. These names are intendedto be generic in their application while differentiating between thevarious details. Corresponding reference characters refer to likemembers throughout the several figures of the drawings.

The drawing accompanying, and forming a part of this specificationdisclose details of construction for the sole purpose of explanation. Itis understood that structural details may be modified without departingfrom the concept and principles of the invention. This invention may beincorporated in other structural forms than shown.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1 and FIG. 2, a first embodiment of a plate compactoris generally identified as 10, This plate compactor 10, includes a motor12 which is removably fastened to a mounting plate 14. Preferably, thismotor is an internal combustion engine. However the use of alternativemotors which are electrically, pneumatically, or hydraulically poweredare anticipated. The mounting plate 14 is selectively shaped andresiliently attached to a tamper plate 16 by a plurality of isolationmounts 22. A guiding handle 24 is connected to the mounting plate 14 forproviding a means for manually guiding the plate compactor 10.Preferably, the guiding handle 24 is rigidly attached to the mountingplate. Alternatively, a pivoted mounting arrangement may be provided toaccommodate folding of the handle for storage or transport.

It is preferred that the motor 12 be centrally mounted with respect tothe tamper plate 16 in order to distribute its weight equally on thesurface being compacted.

The tamper plate 16 includes a tamper side 26 and an opposite side 28.The end portions 29 of the tamper plate 16 may be formed to provide aninclined surface 30.

Referring in particular to FIG. 2, a vibrator assembly 32 includes aweight 34 which is eccentrically carried on a vibrator shaft 36.Selected portions of the vibrator shaft 36 are journaled in a vibratoryhousing 38. At least one end of the vibratory shaft 36 extends aselected distance beyond the housing journals for attachment of a drivenmeans 40, such as a V-belt pulley or the like.

Referring again to FIGS. 1 and 2, the vibratory, housing 38 is attachedto one end of an arm 42. The opposite or distal end of the arm 42 isattached to the opposite side 28 of the tamper plate 16 by a flexmounting means. Preferably this flex mounting means shown in thisembodiment includes an elongated tube 44, as seen more clearly in FIG.2. This elongated tube 44 is pivotally attached to the tamper plate 16by bearing blocks 46. These bearing blocks 46 preferably are sealedpillow block bearings which are commercially available and easilyserviced. The ends of the elongated tube 44 may include shoulderedportions for locating the position of the tube 44 with respect to thebearing blocks 46. It is preferred that the flexing axis of the flexmounting means and the elongated tube 44 be centrally located withrespect to the tamper plate 16. This flexing axis should also betransverse to the direction of self-propelled movement of the platecompactor.

Still referring to FIG. 2, an axis of an intermediate drive transfermeans 48 is coincident with the flexing axis of the flex mounting means.The preferred arrangement for the intermediate drive transfer means 48includes and elongated shaft 50 which passes interior of the elongatedtube 44. Preferably, sufficient clearance is provided between theelongated shaft 50 and the inside diameter of the elongated tube 44 toallow free rotation. Alternatively, additional bearings may be providedin the ends of the tube 44 for additional support for the shaft 50. Theelongated shaft 50 is rotatably mounted by at least two second pillowblocks 52. A first transfer pulley 54 and a second transfer pulley 56are secured to the elongated shaft 50. This preferred arrangement, asshown in FIG. 2, evenly distributes the weight on the tamper plate 16.Alternatively, if weight distribution is not a consideration, the firsttransfer pulley 54 and second transfer pulley 56 may be secured to theshaft on the same side of the compactor. In another example, theelongated tube 44 may be replaced with a solid shaft which hasshouldered end portions. The first transfer pulley and second transferpulley may be made as a unit which is rotatably carried on the solidshaft.

The intermediate drive transfer means 48 provides a rotary V-belt driveto the driven means 40 from a drive means 58. The drive means 58 ismounted to an output shaft of the motor 12. This drive means 58preferably includes a clutch 60 and pulley 62 arrangement forselectively engaging the drive means 58 to the motor 12.

Referring again to FIG. 1, a handle 64 preferably is attached to thevibrator housing 38. This handle 64 allows the user to pivotally swingthe vibrator housing 38 between extreme end positions of the tamperplate 16. It is preferred that direct contact not be made between thevibrator housing 38 and the opposite side of the tamper plate 16. It isrecommended that a pad 66 of vibration absorbing material be providedbetween the vibrator housing 38 and the tamper plate 16. This is toinsure that substantially all forces are directed through the arm 42 andinto the tamper plate 16 by way of the flex mounting means. This desiredtransfer of vibratory motion from the vibratory housing 38 to the flexmounting means provides the directional movement of the plate compactorirrespective of rotation of the eccentric weight 34. The direction andvelocity of the compactor, for a given RPM of the motor rotation, isgoverned by the arcuate positioning of the vibratory housing 38. Forexample, when the vibratory housing is positioned as shown in FIG. 1 themovement of the plate compactor is to the right.

Referring to FIG. 3, the vibratory housing 38 has been swung to itsother extent. The direction of travel will be to the left irrespectiveof rotation of the eccentric weight 34. If the vibratory housing 38 wasto be positioned at right angles to the plane of the tamper side 26,there would be little or no self-propelled movement in either direction.

Referring to FIG. 4, there is shown an alternative flex mounting meansfor locating the vibrator housing 38 at a selected point along itsarcuate path. Selective positioning would provide the user with a meansfor controlling the velocity of self-propelled movement. The elongatedtube 44 is held at a selected angle A by means of a clamping means 68.It is preferred that this clamping means 68 is split to allow easyarcuate movement of the vibrator housing when desired. At least twoclamping screws 70 are used to clamp the tube 44. It is preferred that abore of the clamp means 68 or the outside diameter of the tubing 44 havea layer of resilient material 72 formed thereon for allowing controlledoscillations of the vibratory housing 38 in a direction at right anglesto the arm 42. This arrangement may allow for the elimination of bearingblocks 46. An operator of the plate compactor 10 may selectivelyposition the vibrator housing 38 at any desired angle A in order to varythe self-propelled velocity of the machine. Should the operator needcompaction only, the vibrator housing may be adjusted to an angle in thevicinity of 90 degrees. It has been found that an angle A in the rangebetween 20 and 30 degrees provides satisfactory self-propelled motion aswell as compaction. This flex mounting means may be used with a singlevibrator as described in conjunction with FIGS. 1 and 2 or with anembodiment described below in conjunction with FIG. 5 and 6.

Referring now to FIGS. 5 and 6, an alternate embodiment of the presentinvention is generally identified as 80. Plate compactor 80 includes twovibrator housings 38. Each vibrator housing 38 is connected to theelongated tube 44 by its associated arm 42. Each of the vibratoryhousings 38 is mounted near each end 29 of the tamper plate 16. Eachvibrator assembly 32 is driven by a driven means 40. This driven means40 is preferably a V-belt pulley. Each of the driven means 40 isselectively driven by its associated V-belt 82. A second dual transferpulley 84 includes two V-belt grooves. Each V-belt 82 is sized to allowslippage between the dual transfer pulley 84 and the V-belt 82 unlesstensioned. Tension of each V-belt 82 is independently provided by a pairof tensioning wheels 86. Each of the tensioning wheels 86 is mounted ona rocker-type lever 88 which is pivotally attached to the tamper plate16. The rocker-type lever 88 is pivotally mounted to provide tension toonly one of the V-belts 82 at a time. The rocker-type lever 88 mayinclude a spring loaded toggle arrangement for maintaining the tensionon the selected V-belt. The user would move the handle about its pivotin the direction of the arrow to control the self-propelled movement ofthe plate compactor 80. It is preferred that a vibration isolation pad66 be provided between each of the vibrator housings 38 and the endportions 29. It is anticipated that the isolation pads 66 may be mountedto either the vibrator housing 38 or the end portions 29. Alternatively,the flex mounting means may take the form of the type described inconjunction with FIG. 4.

As in the case of plate compactor 10, the direction of self-propelledtravel is independent of the direction of rotation of the eccentricweight 34 in the vibrator housing 38. The direction of self-propelledmovement of the plate compactor 80 is dependent on which end portion 29the eccentric weight 34 is rotated.

Referring now to FIG. 7, a third embodiment of a plate compactor isgenerally identified as 90. This plate compactor 90 utilizes a vibrator92 which is attached directly to one end of the tamper plate 16. Thistype of mounting relies on the direction of rotation of its eccentric toproduce a self-propelled direction of travel. In addition to thevibrator 92, a vibrator assembly 32 is provided for producingself-propelled travel opposite to the travel produced by vibrator 92.The vibrator housing 38 is attached to an arm 94. The arm is bent orformed to position the vibratory housing 38 at a desired angle withrespect to the plane of the tamper side 26. It is important that thevibratory housing 38 be held in spaced relation with the inclinedportion 30 of the tamper plate 16. The end of the arm 94 opposite thevibrator housing 38 is configured with a flex mounting means. This flexmounting means includes a bent portion of the arm which is sandwichedbetween two layers of an isolation material 96 such as rubber and aretaining plate 98. The flex mounting means is attached to the oppositeside 28 of the tamper plate 16 by threaded fasteners 100.

A pair of V-belts 82 are rotatably driven by a drive means 58. Thisdrive means would require a V-belt pulley having dual grooves. TheV-belts 82 are sufficiently long so that neither pulley 40 is drivenunless tension is applied to one or the other V-belt 82. In thisexample, driving tension is applied by one of the tensioning wheels 86mounted to a rocker-type lever 88. The operation of the tensioning meanshas been previously described. It is anticipated that vibrator 92 may bereplaced with a second vibrator housing 38 and arm 94 assembly which isattached to the tamper plate by this type of flex mounting means.

This third embodiment 90 has particular advantages. One advantage ofthis third embodiment, is that this configuration may be provide as anew piece of apparatus or as a retrofit to an existing uni-directionalplate compactor. A second advantage is the simplicity of the designwhich would make an economical new apparatus or retrofit. A thirdadvantage allows a new vibratory housing 38 to be added to an existingpiece of apparatus irrespective of the direction of rotation of themotor 12.

Terms such as "left", "right", "up", "down", "bottom", "top", "front","back", "in", "out", and the like are applicable to the embodimentsshown and described in conjunction with the drawings. These terms aremerely for the purpose of description and do not necessarily apply tothe position in which the reversible plate compactor of the presentinvention may be utilized.

While a particular embodiment of a reversible plate compactor has beenshown and described, it is to be understood that the invention is notlimited thereto and protection is sought to the broadest extent priorart allows.

What is claimed is:
 1. A reversible self-propelled plate compactorcomprising:a) a tamper plate having a tamper side for contactingmaterial to be compacted; b) a motor carried on a mounting plate, saidmounting plate being selectively shaped; said mounting plate beingresiliently attached to said tamper plate for isolating said mountingplate and said motor from said tamper plate, said motor having a drivemeans attached to an output shaft; c) at least one vibratory assemblyincluding a weight being eccentrically carried on a vibrator shaft forimparting vibratory motion when rotating by way of a driven meansmounted thereon, said driven means being selectively driven by saiddrive means, said vibratory shaft having selected portions beingjournaled in a vibratory housing, said vibratory housing being attachedto one end of an arm, the opposite end of the arm having a flex mountingmeans for attaching to an interior side of said tamper plate, saidinterior side being opposite to said tamper side, a flexing axis of saidflex mounting means being transverse to a direction of self-propelledtravel; and wherein said vibrator housing and said arm being selectivelytilted about said flexing axis at a predetermined angular position withrespect to a plane parallel to said tamper side for directingsubstantially all forces necessary for said self-propelled travel intosaid tamper plate by way of said arm and said flex mounting means, saiddirection of said self-propelled travel being irrespective of thedirection of rotation of said vibratory shaft.
 2. A reversibleself-propelled plate compactor as recited in claim 1 wherein said flexmounting means further includes at least two isolation strips, andwherein said opposite end of the arm is sandwiched between the twoisolation strips.
 3. A reversible self-propelled plate compactor asrecited in claim 2 wherein said opposite end of said arm includes a bentportion which is sandwiched between the two isolation strips, said bentportion being configured for maintaining a spaced relationship betweensaid vibratory housing and a proximal point of said tamper plate.
 4. Areversible self-propelled plate compactor as recited in claim 2 whereinsaid driven means being selectively driven by a drive means includes arocker type tensioning means for selectively applying a driving tensionto a belt drive from said drive means to only one driven means.
 5. Areversible self-propelled plate compactor as recited in claim 1 whereinsaid flex mounting means further includes:a) a pivoting means having itsaxis coincident with said flexing axis, said pivoting means beingconfigured for selectively positioning said vibrator housing along anarcuate path, said arcuate path having said flexing axis as its center,said positioning of said vibratory housing along said arcuate pathdetermining the direction and velocity of said self-propelled travel,and b) an intermediate drive transfer means having its axis coincidentwith said pivoting axis, said intermediate drive transfer means forproviding a rotary drive from said drive means to said driven means atany point along the arcuate path.
 6. A reversible self-propelled platecompactor as recited in claim 5 wherein said pivoting means furtherincludes a clamping means for maintaining said vibrator housing at aselected point along said arcuate path.
 7. A reversible self-propelledplate compactor as recited in claim 5 wherein said flex mounting meansfurther includes at least one isolation pad for maintaining a spacedrelationship between said vibratory housing and said tamper plate atterminating points along said arcuate path.
 8. A reversibleself-propelled plate compactor as recited in claim 5 which furtherincludes two vibratory assemblies, each vibratory assembly beingpositioned at opposite ends of said tamper plate, an isolation padassociated with each vibratory assembly for maintaining a spacedrelationship between said vibratory housing and its associated end ofthe tamper plate, each vibratory assembly having a belt drive from saidintermediate drive transfer means to its driven means, and a tensioningmeans for selectively applying tension to only one of said belt drivesfrom said intermediate drive transfer means to said driven means at atime.
 9. A reversible self-propelled plate compactor as recited in claim6 which includes two vibratory assemblies, each vibratory assembly beingpositioned at opposite ends of the tamper plate, each vibratory assemblyhaving a belt drive from said intermediate drive transfer means to itsdriven means, and a tensioning means for selectively applying a drivetension to only one of said belt drives from said intermediate drivetransfer means to said driven means at a time.